I want to give the same parameters to all paths in Rails.

Use url_options to include the same parameters in all paths of view, controller.

#application_controller.rb
def url_options
  { first: "first", last: "last"}
end

I did it like this, but

redirect_to user_path(name: "aaa")

gives parameters, whereas

redirect_to user_path

The url_options parameter is not included only if you do not have any arguments.
(url_options itself does not pass)
When I looked at the website that showed how to use url_options, I couldn't find this problem anywhere. How do I get parameters?